Cod sursa(job #2981771)

Utilizator SabailaCalinSabaila Calin SabailaCalin Data 18 februarie 2023 17:54:37
Problema Range minimum query Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.12 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream f ("rmq.in");
ofstream g ("rmq.out");

const int SIZE = 100005;
const int LOG = 17;

int n, q;
int st[LOG + 1][SIZE];
int log_2[SIZE];

void Read()
{
    f >> n >> q;
    for (int i = 0; i < n; i++)
    {
        f >> st[0][i];
    }
}

void PreprocessSparseTable()
{
    for (int i = 1; i <= LOG; i++)
    {
        for (int j = 0; (j + (1 << i)) <= n; j++)
        {
            st[i][j] = min(st[i - 1][j], st[i - 1][j + (1 << (i - 1))]);
        }
    }

    for (int i = 2; i < SIZE; i++)
    {
        log_2[i] = log_2[i / 2] + 1;
    }
}

int log2_floor(unsigned long long i) {
    return i ? __builtin_clzll(1) - __builtin_clzll(i) : -1;
}

void Print()
{
    for (int temp = 1; temp <= q; temp++)
    {
        int left, right;
        f >> left >> right;
        left--;
        right--;

        int i = log2_floor(right - left + 1) - 1;
        g << min(st[i][left], st[i][right + 1 - (1 << i)]) << "\n";
    }
}

int main()
{
    Read();
    PreprocessSparseTable();
    Print();

    return 0;
}